Sharing: precision steel pipe fire protection measures
1, outsourcing layer. Outsourcing is in auto precision steel tube appearance add layer, can cast-in-situ forming, spraying method can also be adopted. Cast-in-situ molding outsourcing entities concrete layer Cold Drawn Steel Tubes usually use steel wire or steel to strengthen, to limit the shrinkage crack, and secure shell Strength. Spraying method in the construction site of the steel tube surface daub sand pump to form a protective layer, sand pump can be cement or lime chemical formula: CaSO4 · 2 h2o mortar, can be mixed with perlite or asbestos. Also can use the perlite, stone layer of outsourcing Cotton, gypsum or asbestos cement, lightweight concrete precast slab, using adhesives, nail, bolt on the auto precision steel pipe.
2, water filling. The hollow steel tube filling water is a protective measures against fire. This method can make the steel pipe in the fire to keep low temperature, the water circulate in the steel pipe, the quantity of heat of heat absorption material itself. The heated water can be recycled after cooling Introduced by pipeline, or cold water to replace the heated water.
3, shielding. Auto precision steel tube set in fire prevention materials consisting of a wall or ceiling, or component parcel in the space between the two pieces of wall, as long as increasing a few refractory or not can accomplish the purpose of the fire. This is a very economic fire Methods.
4, expansion material. Using fire-retardant coating protection component, this method has good fireproof and heat insulation performance, construction from the geometric limit etc, generally do not need to add auxiliary Cold Drawn Tubes facilities, and the coating quality is light, and beautiful adornment effect, belonging to the modern Good fire prevention technical measures.
Control of automobile muffler welding stress points are as follows:
One, reduce the welding at home: at home, the greater the welding stress is larger, should try to make the welding seam in smaller constraint degrees, rigid fixation method to control deformation as far as possible need not, lest increase welding at home.
Second, to reduce the weldment stiffness, have free contractive conditions.
Three, to decrease the size of weld: welding stress caused by local heating cycle, therefore, under the condition of meet the design requirements, should not increase weld size and height, turn to weld the bigger the safety concept.
Four, hammering method to reduce the welding residual stress, in each room after the bead welding with small round head tapping slag hammer or electric hammer evenly on weld metal tools, make its produce plastic deformation, and to precision welded tubes accept the local tensile stress of weld offset after cooling.
Five, adopt reasonable welding sequence: under the condition of more welding assembly, components according to the shape and arrangement of welds, adopt welding shrinkage larger weld first, after welding the weld of the smaller shrinkage, larger welding at home first and not free shrinkage of welding Seam, welding constraint degree and smaller contract freely after the principle of weld.